<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			*{
				margin: 0;
				padding: 0;
			}
			.div1{
				width: 200px;
				height: 200px;
				background-color: red;
			}
			.div2{
				width: 100px;
				height: 100px;
				background-color: green;
			}
			span{
				background-color: red;
    			padding: 10px;
			}
			p{
				background-color: blue;
    			padding: 10px;
			}
			div{
				border: 2px solid blue;
			}
		</style>
	</head>
	<body>
		
		<div class="div1">
			<div class="div2">
			</div>
		</div>
		
	
		<!--<span>我是span元素</span>
		<p>我是p元素</p>-->
		
	</body>
</html>
